Refrigerating system



Feb. 16, 1932.

A. c. SCHICKLER l,845,060

REFRIGERATING SYSTEM' Filed Oct. 27, 1926 4 Sheets-Sheet l v Feb. 16, 1932. A. c. scHlcKLER REFRIGERATING SYSTEM 4 Sh-e'ets-Slneet 2 Filed oct.' 27, 192e Feb. 16, 1932. AA Q SCHCKl- ER 1,845,060

REFRIGERATINQ SYSTEM v Filed Oct. 27. 1926v 4 Sheets-Sheet 3 4 7 I gwuenfoz fb 16, 1.932 l A. scHlcKLl-:R r A1,845,060

REFRIGERATING SYSTEM Filed oct. 27. '1926 i sheets-sheet 4 Patented Feb. 16, 1932- y UNITED STATES PATENT OFFICE- ALBERT C. SCHICKLER, F CLEVELAND, OHIO, ASSIGNOB TO EDM'UND'E. ALLYNE, 0F CLEVELAND, OHIO p nnrmeanarrne sYsTinr This invention relates to refrigeration, and

, more particularly to refrigerating systems of the absorption type, Where a suitable refrig-y erant, such as ammonia, is intermitently distilled from a suitable absorbing agent, `such as Water, and is condensed and collected in an evaporator during the first half of the cycle, and then during the second half of the cycle, is evaporated inthe eva orator toLproduce the refrigerating effect, eing returned to and distributed in the absorbing agent the boiler, now functioning as an absorber.

The invention has for its objectf to provide lan eiiicient refrigerating system which may be effectively sealed .and which avoids anyv necessity of valves or stung boxes, with their possible leaks or loss of pressure and eiiciency, or internal Workino parts which get out of order and interfere with proper operation.

A further object is to provide a system of this kind with a very eiicientboiler in which heat is produced by applying electrical energy directly to the liquid in the boiler, with immediate heating effect, thereby reducing the heating period and avoiding loss cf energy. l

A further object is to provide an improved electric heater in which heat is produced byA the resistance to current flow of the liquid absorbing agent, together with improvementsi in the arrangement of the electrodes, 'their levels for safety purposes, their mounting and insulation from each other, and their provision with means for inducing circulation of the boiler liquor. A

A further object is to provide `a system which returns to the still-absorber all absorbing agent carried to other parts of the apparatus, such as to the evaporator, either entrained in the gaseous refrigerant durin distillation orcarried. to the evaporatorby'a boil over, such as sometimes occurs in absorption systems, and an arrangement for this purpose which compels the distilled gaseous refrigerant to follow its customary .path'for condensation and collection in the evaporator and for return to the absorber, but which supplies a separate gravity return path from the evaporator to the boiler for absorbing agent, such as Water, or for the heavier aquaammonia, but which also prevents any flow of the gas or liquid through the latter 'path I from-the boiler to the evaporator.

` A further object is to provide an absorption refrigeratin system embodying an evaporator locate at a higher level than the boiler and a free'gravity return path for heavier li uid from' the evaporator to the boiler, but 1n vwhich path suitable means, such as a hydrostatic seal, prevents return of other than the heavier liquor, the presence of which 1n the "evaporator, is undesirable, and also prevents gas or liquid flow from the boiler` to thsevaporator except through proper chanine L A furthe'r'object `is to provide an improved 4liquid, or hydrostatic seal inv which the sealing liquid has av density greater than water or I anhydrous ammonia and is trappedin a U tube of special form, enabling application of the-opposite ends of the liquidin said tube of columns of aqua-ammonia or ammonia, as the case may be,"and yet in which the sealing liquid is trapped in the-U-tube against' possible escape, -such as by physical inversion of theA apparatus, which' 'might occur during' shipping or prior t`o installation. s Stilll another object is lto provide anautomatic control system,'including means for shifting from the heating to the-refrigerating period of the cycle and backagain, atV

the proper times, and vparticularly such a means controlled `by or inaccordance with the level of liquid in one ofthe containing vessels therefor, such as the boiler,-coinpelling heatin and distillation at one time and equally cutting oil the heat and starting refrigeration at another time. A A -further'object is the organization in or with such anl automatic control system of a thermo-Siphon cooling system for the boiler, or, in other words, one in which a mass of cooling liquid, such as water, is permitted to circulate or isb trapped-without circulation vaccording to the desirability of cooling the boiler during absorption or of preventing the abstraction of heat therefrom during boiling. Further objects of the invention are in part obvious and in part will appear more in de- 100 tail hereinafter.

'ris

In the drawings, which represent one suitable embodiment of the invention, Fig. l is a rear elevation, partly broken out, of a refrigerator embodying the apparatus and particularly illustrating the piping system, mostV of the electrical control features being omitted for simplicity of illustration; Fig. 2 is a simplified diagram of the circulation system, prepared for convenience in explanation; Figs. 3, 4 and 5 are detail sectional views, on a larger scale, illustrating the U-tube and liquid seal in various positions to which it may be turned by inversion of the entire apparatus; Fig. 6 is a. detail longitudinal section through the boiler; Fig. 7 is a detail sectional elevation, on a larger scale, o n the line 7-7, Fig. 6. and illustrating the heating elements; and Fig. 8 is a diagrammatic view illustratingr the electric control system.

Referring to Fig. 1 the apparatus forming the subject matter of the present invention is applied to a household refrigerator. including a casing or jacket 1 resting on the fioor and provided with a horizontal cross wall 2 forming the floor of the insulated refrigerating chamber 3 and the roof of a non-insulated chamber or space 4 within which most of the working parts are contained, a convenient arrangement because it avoids stooping to manipulate the materials in the refrigerating chamber and stores the working parts in space of less value for refrigerating purposes. In the lower space 4 islocated a relatively large tank 5 adapted to receive a mass of suitable cooling liquid` such as water, any heat in said tank readily radiating through its walls to the atmosphere. The bottom portion of the space 4 contains the boiler 6 and above it a small sealed receiver 7.

As shown in Fig. 6, boiler 6 is of generally cylindrical or drum form, being completely sealed against the atmosphere and being provided with a suitable water acket, such as the sheet metal enclosure or envelope 8, spaced by the knobs or heads 8a and welded in place at one end and communicating at a high point by the pipe 9 and valve 10 with the upper poltion of the cooling tank 5, and also communicating at a low point by the pipe 11 with a low point in the cooling tank. The chamber within the boiler 6 contains the electric heating elements. later to be described, and the gas space in the boiler communicates by an inverted U-pipe 12 with the receiver 7, the end ofthe pipe 12 opening at a low level in said receiver. Drainage or return from the receiver to the boiler is provided by the pipe 13, of ample cross sectional area, the upper end of which extends up through the bottom of the receiver and terminates therein at a level above the bottom of pipe 12, and the lower end of which pipe 13 may have one or more perforated branches 13a'for distribution throughout the absorbing agent of the gas returned for absorption therein.

From the top of the receiver 7 extends a pipe 14, the first portion of which is of relatively large size and is inclined upwardly and may be bent back and forth, as shown, to form a rectifier, in which a'large proportion, if not all, of the water entrained in the gaseous refrigerant may collect and from which it drains back into the receiver 7 and thence into the boiler. However, such rectifiers are usually exposed to the outside air, which may be cool, and therefore many condense some ammonia which is returned to the boiler without the production of a useful refrigerating effect. Because the present system provides an efficient means and method of unimpeded return to the boiler of practically all absorbing agent carried over to the evaporator, it is not so important to rectify the distilled gas, but the entrained absorbing agent or the effects of a boil over may be taken care of even if it reaches the evaporator. Therefore, a large proportion of the pipe coils of the rectifier may be omitted and the gas may be led directly from the top of the receiver 7 through one pass of pipe 14 to the condenser 16, as shown in Fig. 2. s

The condenser `consists of coils or convolutions of pipe of small size located at any suitable level and, as shown, being located in the cooling liquid in the tank 5, the distilled gas being supplied to the upper convolutions of the condenser and the condensed refrigerant flowing to the bottom, from which the' ipe 17, also of small size, leads to the top o the evaporator 18, which is shown as of simple drum form, but which may be of any suitable shape or configuration. To increase efficiency the condenser pipe may be provided with heat radiating means, such as a series of washerlike fins 16a distributed at intervals along its length.

The apparatus so far described is in one sense a simple absorption type refrigerating system. The receiver 7, U-tube 12 and pipe 13 function according to Vllsie Patent No. 1,186,463,- granted June 6, 1916, to compel the gas distilled in the boiler to trav-el through the pipe 12 to the receiver and thence through pipe 14 to the condenser, but during the re. frigeratingperiod compel the gas returning through pipe 14 to enter the boiler through pipe` 13 and bubble up through the absorbing agent to be absorbed thereby. Pipe .13 is purposely made of large cross sectional area to avoid clicking said pipe, such as by the sudden discharge from pipe 14 of a collection of drops of liquid, a choking which might permitthe level of liquid in the receiver to rise high enough to cause some liquid to be forced ovei into pipe 14 and surge into the condenser, or in other words to start a boil over. The large size of pipe 13 also provides a .copious and quick path for the gas returning to the boiler.

In the present apparatus the return of the heavier absorbent` nbearingfliquor `from the evaporator tothe boiler occurs through a pipe 19, communicating with the bottom of the evaporator and leading to one leg or chamber of .the two communicating chambers of a hydrostatic seal of generally'U-form, marked 20, theother leg orchamber of which communicates by pipe 25 with the bottom of receiver 7. The hydrostatic sealing device contains a quantity of sealing 'liquid 21, more dense than the absorbing agent or'refrigerant, such as water and ammonia, and which in quantity must be delinite, with due regard to the sizeand configuration of the U-tube walls and to the column of liquid in the pipe 19. It must also be a substance which is not aiiectedby the absorbing agent, such as water, or by the refrigerant, such as ammonia, Aor vin the present instance, by any reagent which may be added to the liquid to prevent the production of inert orl useless gas, such a rea ent, for example, being sodium bichromate. ne suitable sealing liquid for use with water, ammonia and sodium bichromate ismetallic mercury. The amount of mercuryl must be such that when all of itis moved toward the 'stffill and into one leg of the U-tube, or to suchposition that waterl or ammonia can Ypassthe bottom of the U-tube, then the effective height of the maximum mercury column is of greater" vvalue than and -will overbalance a column of anhydrous ammoniaxlling pipe 19v to thetop of the liquid in the evaporator, but is of less value than and will beoverbalanced by a column of water or aqua-ammonia in the pipev 19 to the same level. Sincethe density-of mercury is about'13-6 and ammonial solutions have a density of about .8, it is clear that i'f the evaporator, which must always be higher` than the boiler, is 4-O inches above the boiler, the maximum mercury column must be ap-` proximately 2% inches high.4

Referring now to the diagram in F ig. 2,

the apparatus, and more particularly the mercury seal, operates as follows: i

As a general rule the level of liquid in rel ceiver 7 is at the top of the pipe 13. During the boilingoperation the distilled gas passes,A over to receiver 7 and thence to the condenserf' cient to fully depress its leg of the U-tube,

so that no liquid or gas can flow past` the U-tube from receiver 7 to the pipe 19, but distillation goes on with supply off gas to the condenser until the liquid collected therein is lifted by the increasing pressure and is discharged into the top of the evaporator,

"Itablished v v As-indic'ated in `Figa, Lland 5, the mercury seal or U-tubeis of special form- While from which, of course, it flows downwardly through pipe'19 to be supported on its mercury leg. The arrangement, it has been said, is such that the maximum mercury column willsupport the full liquid column in pipe 19 if said column is of approximately anhydrous ammonia, but will not support the full column if it is of heavier, absorbent bearing liquor or aqua-ammonia. Consequently, ammonia and water delivered to the evaporator are collected by the pipe 19, the heavier liquor or water collecting at the bottom until the weight of the liquid column, by additions of heavier liquor or' aqua-ammonia, overbalances the maximum mercury leg, whereupon some of the heavier liquor at the mercury leg flows back and enters the bottom of the receiver 7 and drains to the boiler. The net effect is to establish and maintain in pipe 19 a level of contact between the heavier aqualammonia and approximately anhydrous amthe apparatus. In case of a boil over it is obvious that no matter how great the quantity of aqua-ammonia delivered to the evaporator -it promptly gravitatesy back through pipe 19 and past the mercury seal to the boiler `until normalconditions are again.` esthe cavities and channels therein are the essential thing'. and may-be cored out or' formed in any suitablmaterial' un'aiected by mercury,"su`ch as cast iron', yet in practice it may be made of a section of tubing 22 bent to U YVform, v.the ends V'thereof being enlarged to form wells 23 closed attheir. upper ends by walls 24through'which the ends ofthe-pipe members 25, 19 extend."-The ends of said pipes extend into the wells to about *theirYr I centers, 'where'y they are suitablybaliled, such as by being closed bv end wallsl orcaps 27,

.one or a number of sinall holes-28 vbeing provided in the side walls of the pipes through which the absorbing agent may flow.- The wells 23 are -Inade` of such size thateven if `the entire refrigerating apparatus; including the U-tube,is turned on one sfide, 'as in Fig. 4, or is even completely inverted as in Fig. 5, the upper surface 21a'l of the mercury,

even if all of the same` is collected ,in one well,.will be below and out of contact with the openings 28. By baffling the ends of the pipes with the caps 27, and by providing wells of sufficient size, as described, it is practically impossible for any of the sealing agent, such as mercury, to escape under any conditions.

The boiler heater, in the present apparatus, is of special form. It comprises two conducting elements insulated from each other but relatively closely spaced, the A. C. current conducted to them being caused vto How across the gap and by overcoming the resistance of the liquid to heat the same. These electrodes are preferably arranged in a manner to promote liquid circulation during the heating operation. As indicated in Figs. 6 and 7 one of the electrodes 29 is of hollow tubular form with its axis vertical, being welded or otherwise permanently located within the boiler and thereby establishing conductive relation with its shell. Suitable openings 0r recesses are provided near the bottom of electrode 29 to insure free communication and flow of liquid from the outside to the inside of the electrode at its bottom. If the boiler is of cylindrical Jorm and electrode 29 is also of cylindrical form with its bottom cut off square, as in Fig.v7,.1`t can be perched in the boiler and welded at two op osite points, as at 29a, so as to leave gaps 29 between its lower edge and the boiler wall, but additional recesses 30-may be provided if desired.

j'Within the upper end of electrode 29 is mounted the cooperating electrode 31, which isof disc form in plan view and which is coaxialwith the tube 29 and is properly sized and spaced according to the desired heating effect.- As shown, said electrode 31 is mounted fast upon an insulating porcelain tube 32 sleeved upon a bolt 32a extending through alined openings in member 29, a pair of in'- sulating spacers 33 separating the electrodes from each other.

lVith this arrangement, by connecting electrode 31 to one side and electrode 29 or the shell of the boiler to the other side of an A. C. electric circuit with proper power rating, current flows across the gap between the two electrodes so long as they are sufficiently immersed in the absorbing. agent, the current effect heating the liquid and causing it to rise within the tube 29 and flow over the upper edge thereof, being replaced by additional liquid flowing into the tube 29 through recesses`29b and 30. In the practical operation of this system the quantity of liquid is preferably so chosen that in ordinary operation its upper surface never drops below the level of the top of tube 29, so that rapid circulation always occurs with a uniform heat- .ing effect when the heater is in operation.

However, one of the electrodes, such as electrode 31, is placed at a level above the bottom of the boiler and particularly at such a level that in case the control circuits or devices fail to work or operate incorrectly, or in case for any reason the heating current is continued indefinitely, the level of liquid finally drops below said electrode 31, automatically interrupting or opening'the heating circuit. The level of electrode 31 is such that this occurs before the pressure and temperature of the boiler rise toany unsafe degree. The boiler is therefore automatically safeguarded against dangerous conditions from overheating.

Fig. 8 illustrates diagrammatically the control circuits anddevices, which include two switch members 35, 36 mounted to rock simultaneously upon an axis indicated at 37, such as by being mounted in a suitable rocking frame having an operatingl member, such as the arm 38, connected for operation to the core 38a of an electro-magnet. Switches 35 and 36 may be of any suitable form answering to the requirements, although they are shown as of the mercury form, including a chambered insulating casing, such as of glass, preferably evacuated and containing a. small lnass of mercury adapted to close the circuit through one or more pairs of contacts, as will appear. Switch 35 has two such-pairs of contacts marked respectively 39, 40, while switch 36 hasta single pair of contacts 42. The last named contacts 42 are in a circuit from L1 by way of wire 43 to the electrode 31. Insulated connection to said electrode through the wall of the boiler may be secured by using a device 34 similar to a spark plug, to the outer end of the conducting member of which the lead wire is secured, and the inner end of which is cupped to make. contact with a resilient wire 44 fastened to electrode 31. i l

Contacts 39 are in a circuit from L1 by way of wire 45 t o said contacts, thence through a coil 46 and wire 47 to ashort terminal 48 passing through the porcelain center of another special spark plug.l Contacts 40 are in another circuit from L1 including Wire 49, said contacts, a coil 50, and wire 51 to a long terminal 52 passing through the porcelain center of the same spark plug: The metal shell of said spark plug, which is screwed into a fitting inthe wall of the boiler, has short and long terminals 53, 54 Within the boiler. The several terminals of this spark plug are in pairs, terminals 48 and 53 being short and terminating at the desired upper level A of liquid in the boiler. Terminals 52 and 54 are longer and terminate at the desired low level of liquid in the boiler, a level just above the top of the tube 29, as indicated by ,the line B. The shell of the boiler is grounded to L2 by wire 55.

Suitable connections are also provided for actuation of the thermo-Siphon valve 10, the operating handle 61 of which is connected by the rod 56 to thecore 57 of a solenoid including two coils 58, 59. Movable with the core is an insulating block 60 carrying a resilient contact blade 52 adaptedin the two positions of the core to engage relatively stationary contacts 63, 64. A flexible lead from the wire 65 connects the blade 62 to L2 and the two coils 58 and 59 are respectively in branch circuits 66, 67, one from the contacts 39 to contact 64 and the other from the contacts 40 to the contact 63. The core 57 is when thel system has just begun the refrigerating portion of its cycle. The level of liquid in the boiler l6 is low, the heat is cut off because' the mercury in switch 36 is `at the opposite end of its tube from contacts 40 and the core 57 is in the full line position with the valve 10 open. The colder water at the bottom of the thermo-Siphon tank therefore Hows into the bottom ofthe water jacket around the boiler, the warmer liquid in said jacket rising'and flowing into the top of the thermo-Siphon tank.' This shot of colder liquid starts the absorbing operation and the. gas evaporated in the evaporator returns to the' boiler andl isV absorbed therein. At the. beginning of the refrigerating operation, as will appear, the level of liquld has lowered to such a point that both of the terminals 52,l 54 are out of contact with the liquid or are immersed only very slightly, tosuch ank extent that negligible' current fiows between them. During refrigeration the` level of liquid in the boiler rises andv almost immediately said terminals 52, 54 are immersed, but no special effect follows because the con,- tactsI 40 are open. Finally the levelof liquid rises to approximately the level A, Fig. 8, or,

`to a level at which theends of them'embers 48, 53 are sufficiently immersed in the liquid to conduct enough current from L1 to L2 to energize coil 46.V A material `immersion 1s, necessary and actuationo'f the coil 46 will not be caused by mere drepsufliquid which may chance to lodge enmembers 48, 53. However, lwhen sufficient immersion occurs coil 46 is energized and' elevates the core 3 80; to the position shown in dotted lmes Fig. 8, thereby rockin ,the switch carryng frame and turning the switch tubes to their second position. 'As they turn the mercury masses roll to the right hand ends of the switch tube's. :That mercury in tube 35 closes a circuit across thercontacts 40 as soon as it reaches Vthem,witl1ftwo effects. First, it energizes I' over the core 57 to its dotted line position coil 59 with a rush of current which slams Fig."y 8, thereby closing` the thermo-Siphon valve 10 and stopping further water circulation, and also breaking the circuit through coil 59 and closing a new circuit through coil 58. Core 39 is of course raised with a slam, due to the full current effect through coil 46, and rocking motion of the switch carrying frame immediately opens the circuit through said coil at contacts 39. The second effect of closing the circuit at the contacts 40 is to energize coil 50' which remains effective as a I holding coil to hold the frame in its new position until the termination of the boiling operation. The movement of switch 36 t0 its'second position closes the circuit through contacts 42 and supplies current for heating purposes, the liquid boiling and circulating in the boiler and the gas being driven over for condensation as described. vThe fiow of current through coil so continues so long as members ,52, 54 are materially immersed in the liquid, but when the level thereof drops to level B and sufficiently reduces the area offliquid contact and the conductivity between contacts 52,54, said coil is cle-energized and the rocking frame returns by gravity to its former position shown in Fig. 8, Whereupon the circuit 66 through contacts 39 and ncoil 58 is completed,I slamming over the core 57 to its full line position Fig. 8, opening the thermo-Siphon valve, and resetting the circuit to coil 59 for the next operation.,

rlhe arrangement of the control circuits and devices for valve 10 is of especial importance because it always keeps the valve l0 in the prop-er position, open or closed, to be in step with the boiling and refrigerating operations, and is unaected by accidental opening of the main line circuit for any reason or at anv time.

To protect the system against any possible overheating ofv the boiler the latter may be provided with an external Well 7 0 closed by an insulating member, such as a fiber disc 7l, through which two leads of the circuit 43 extend to a fusible wire or link 72. As a result, if the temperature of the boiler rises beyond a dangerous maximum the link 72 lso ing as supports for one or more trays 74 designed for the freezing of ice' cubes, as is customary. The approximate level of contact beneath the approximately anhydrous ammoniaI and the heavier aqua-ammonia or water is usually at a level below these passes 73 which thereby contain substantially anhydrousl ammonia and function as a portion of the evaporator duringV the refrigerating operation. Freezing of the ice in the trays is rapid/'because the trays are located directly beneath the cold evaporator and are supported by refrigerating pipes. Also, the ice cubes are found not to melt so rapidly. during the boiling period when the trays are located asshown.

What I claim is:

1. `Absorption type refri erating apparatus, comprising a still-absor er, a condenser, an evaporator, a drainage conduit from the bottom of the evaporator capable at all times of completely draining the evaporator, said conduit including communicating chamber parts containing a `liquid heavier than any of the liquids in said apparatus unaffected by any of the gases or liquids in said apparatus andv arranged in two columns which permit free drainage'from the evaporator 'of undesirably present absorbing agent but prevent drainage of useful refrigerant.

2. Absorption type refrigerating apparatus, comprising a still-absorber, a condenser, an evaporator, a drainage conduit from the bottom of the evaporator capable at allgtimes of completely draining the evaporator, said conduit including communicating chamber parts containing mercury in two columns which permit free drainage from the evaporator of undesirably present absorbing agent but prevent drainage of useful refrigerant.

3. Absorption type refrigerating apparatus, comprising a still-absorber, a condenser, an evaporator, a drainage conduit from the bottom of the evaporator capable at all times of completely draining the evaporator, said conduit including communicating chamber parts containing mercury in two communieating-columns which permit free drainage from the evaporator of undesirably. present absorbing agent but prevent drainage of useful refrigerant, said chamber .parts being provided with means preventing escape therefrom of the mercury upon change in position of the apparatus.

4. Absorption type refrigerating apparatus, comprising a still-absorber, a condenser, an evaporator, a drainage conduit from the bottom of the evaporator capable at all times of completely draining the evaporator, said conduit including communicating chamber parts containing mercury in two communieating columns which permit free drainage from the evaporator of undesirably present absorbing agent but prevent drainage of useful refrigerant, the chamber parts of the conduit being provided with Wells trapped from the conduit ends to prevent escape of the mercury into said conduits when the apparatus is inverted.

5. A hydrostatic sealing device for refrigerating systems, comprising a U-tube containing sealing liquid, the legs of the Utube being connected to circulating conduits, and means for preventing escape of the sealing liquid into said conduits upon inversion of the device.r

6. A hydrostatic sealing device for refrigerating systems, comprising a casing provided with two chambersv containing sealing liquid and communicating below the upper surface of the sealing liquid therein, the two chambers being connected to circulating conduits, and means for preventing escape of the scaling liquid into said conduits upon inversion of thc`dev1ce.

In. testimony whereof I hereby aiiix my signature. c

ALBERT C. SCHICKLER. 

